[MODEL] Adding Support for Qwen3.5 Models

docs/models/supported_models.md

@@ -738,6 +738,8 @@ These models primarily accept the [`LLM.generate`](./generative_models.md#llmgen
 | `Qwen2VLForConditionalGeneration` | QVQ, Qwen2-VL | T + I<sup>E+</sup> + V<sup>E+</sup> | `Qwen/QVQ-72B-Preview`, `Qwen/Qwen2-VL-7B-Instruct`, `Qwen/Qwen2-VL-72B-Instruct`, etc. | ✅︎ | ✅︎ |
 | `Qwen2_5_VLForConditionalGeneration` | Qwen2.5-VL | T + I<sup>E+</sup> + V<sup>E+</sup> | `Qwen/Qwen2.5-VL-3B-Instruct`, `Qwen/Qwen2.5-VL-72B-Instruct`, etc. | ✅︎ | ✅︎ |
 | `Qwen2_5OmniThinkerForConditionalGeneration` | Qwen2.5-Omni | T + I<sup>E+</sup> + V<sup>E+</sup> + A<sup>+</sup> | `Qwen/Qwen2.5-Omni-3B`, `Qwen/Qwen2.5-Omni-7B` | ✅︎ | ✅︎ |
+| `Qwen3_5ForConditionalGeneration` | Qwen3.5 | T + I<sup>E+</sup> + V<sup>E+</sup> | `Qwen/Qwen3.5-9B-Instruct`, etc. | ✅︎ | ✅︎ |
+| `Qwen3_5MoeForConditionalGeneration` | Qwen3.5-MOE | T + I<sup>E+</sup> + V<sup>E+</sup> | `Qwen/Qwen3.5-35B-A3B-Instruct`, etc. | ✅︎ | ✅︎ |
 | `Qwen3VLForConditionalGeneration` | Qwen3-VL | T + I<sup>E+</sup> + V<sup>E+</sup> | `Qwen/Qwen3-VL-4B-Instruct`, etc. | ✅︎ | ✅︎ |
 | `Qwen3VLMoeForConditionalGeneration` | Qwen3-VL-MOE | T + I<sup>E+</sup> + V<sup>E+</sup> | `Qwen/Qwen3-VL-30B-A3B-Instruct`, etc. | ✅︎ | ✅︎ |
 | `Qwen3OmniMoeThinkerForConditionalGeneration` | Qwen3-Omni | T + I<sup>E+</sup> + V<sup>E+</sup> + A<sup>+</sup> | `Qwen/Qwen3-Omni-30B-A3B-Instruct`, `Qwen/Qwen3-Omni-30B-A3B-Thinking` | ✅︎ | ✅︎ |

tests/models/registry.py

@@ -967,6 +967,16 @@ def check_available_online(
         max_model_len=4096,
         min_transformers_version="4.57",
     ),
+    "Qwen3_5ForConditionalGeneration": _HfExamplesInfo(
+        "Qwen/Qwen3.5-9B-Instruct",
+        max_model_len=4096,
+        min_transformers_version="5.1.0",
+    ),
+    "Qwen3_5MoeForConditionalGeneration": _HfExamplesInfo(
+        "Qwen/Qwen3.5-35B-A3B-Instruct",
+        max_model_len=4096,
+        min_transformers_version="5.1.0",
+    ),
     "Qwen3OmniMoeForConditionalGeneration": _HfExamplesInfo(
         "Qwen/Qwen3-Omni-30B-A3B-Instruct",
         max_model_len=4096,

vllm/config/model.py

@@ -1218,8 +1218,8 @@ def get_num_layers_by_block_type(
             if attn_type_list:
                 return sum(t == 1 for t in attn_type_list[start:end])
 
-            # Hybrid model Qwen3Next
-            layer_types_value = getattr(self.hf_config, "layer_types", None)
+            # Hybrid model Qwen3Next Qwen3.5 Series
+            layer_types_value = getattr(self.hf_text_config, "layer_types", None)
             if layer_types_value is not None:
                 if block_type == "attention":
                     return sum(

vllm/config/speculative.py

@@ -37,6 +37,7 @@
     "ernie_mtp",
     "exaone_moe_mtp",
     "qwen3_next_mtp",
+    "qwen3_5_mtp",
     "longcat_flash_mtp",
     "mtp",
     "pangu_ultra_moe_mtp",
@@ -263,6 +264,16 @@ def hf_config_override(hf_config: PretrainedConfig) -> PretrainedConfig:
                 {"n_predict": n_predict, "architectures": ["ExaoneMoeMTP"]}
             )
 
+        if hf_config.model_type in ("qwen3_5", "qwen3_5_moe"):
+            is_moe = hf_config.model_type == "qwen3_5_moe"
+            hf_config.model_type = "qwen3_5_mtp"
+            n_predict = getattr(hf_config, "mtp_num_hidden_layers", None)
+            hf_config.update(
+                {
+                    "n_predict": n_predict,
+                    "architectures": ["Qwen3_5MoeMTP" if is_moe else "Qwen3_5MTP"],
+                }
+            )
         if hf_config.model_type == "longcat_flash":
             hf_config.model_type = "longcat_flash_mtp"
             n_predict = getattr(hf_config, "num_nextn_predict_layers", 1)

vllm/model_executor/layers/mamba/abstract.py

@@ -43,7 +43,8 @@ def get_state_dtype(self) -> tuple[torch.dtype, ...]:
     def get_kv_cache_spec(self, vllm_config: VllmConfig) -> KVCacheSpec | None:
         if (
             vllm_config.speculative_config is not None
-            and vllm_config.model_config.hf_config.model_type not in ["qwen3_next"]
+            and vllm_config.model_config.hf_config.model_type
+            not in ["qwen3_next", "qwen3_5", "qwen3_5_moe"]
         ):
             raise NotImplementedError(
                 "Mamba with speculative decoding is not supported yet."